In a heterogeneous replication environment, parallel DSI must ensure that the commit order in the replicate database is same as in the primary database.
DSI can then resolve deadlock conflict, when deadlock has occurred, and Replication Server can rollback transactions and execute again.
Replication Server provides other options for maximizing parallelism and minimizing contention between transactions. For example, transaction serialization methods allow you to choose the degree of parallelism your system can handle without conflicts.
For detailed information on how to use parallel DSI threads, see Replication Server Administration Guide Volume 2 > Performance Tuning.